I made this *exact* map a few years ago, only mine had levels of increasing difficulty. Lemme go snag some screenshots.

For proof:

Pitfallv5b2 is the oldest iteration, "Pitfall!" is one I made years later that was completely reconstructed to be more efficient (as I had gained a lot more experience with mapping by then).

The bottom of every pit teleported you to a nest at the top of the next pit. The goal was to make it through without dying.

The levels got increasingly difficult, this one had spinning spirals, and there were other ones that had small, moving holes you had to fall through. Made it for counterstrike, though you could play it in gmod with mp_falldamage (or whatever) set to 1.

I never completed it because I never thought it would generate interest, being as simple as it is.